Magochi (Bartail Flathead): Japan’s Summer Surf Fish and Why Big Ones Are All Female

Fish for flounder on a Japanese surf beach and sometimes you hook something heavy that does not run. Up comes a flat head and a big mouth: magochi, the bartail flathead (Platycephalus sp.). Some anglers are disappointed it is not a flounder — they should not be. Magochi is a prized summer fish that rivals flounder on the table, and you can target it.

Basic data

“Teri-gochi”: a white fish that is best in summer

Most prized white-fleshed fish are best in winter, but magochi peaks in midsummer — hence “teri-gochi” (“blazing-sun flathead”). Summer is when it recovers after spawning and puts on fat. That makes it the perfect partner to flounder: the same beaches, but in the season flounder fishing slows.

Big flathead are all female

Magochi are protandrous: they start as males and change to females as they grow, mostly around 40 cm. So a 50 cm+ flathead is almost certainly female — a spawning fish, which is a good reason not to keep too many big ones.

How it differs from flounder

Flounder will hit lures tens of centimetres off the bottom; flathead need them much closer. Most anglers who cannot catch flathead are running their lures too high.

• Let the lure touch bottom.
• Retrieve slowly as if tapping the bottom, or lift and fall.
• Every 3–5 turns, find the bottom again.

Re-finding the bottom is almost everything. Soft plastics on jigheads, drop-shot or Texas rigs help; metal jigs work too if you keep them near the bottom.

The fight

In a word: heavy. It does not run or pull much, it just feels like dragging rubbish — until it shakes its head hard in the shorebreak. “I thought I was snagged, then it moved” is classic flathead. Their mouths are hard, so make sure the weight is fully on before you set the hook.

Handling: the gill spines are dangerous

This is the most important part. Magochi have sharp, hard spines around the gill covers that can go deep into your hand — and they suddenly jump when you hold them.

• Grip the lower jaw with a fish grip; do not hold it bare-handed.
• If holding the head, press the flat area behind the eyes from above.
• Never put fingers near the gill covers.
• Remove the hook before taking photos.

Tackle

Your flounder surf tackle works as is.

Eating

Magochi sashimi is superb — translucent white flesh sometimes compared with fugu, classic as thin slices with ponzu. Tempura, arai and shabu-shabu are great too. The head is big and bones are thick, so a 50 cm fish gives less meat than you expect. Bleed it by cutting at the gill base, chill without letting fresh water touch the flesh, and rest it about a day for more flavour.

Read next

• Japanese flounder (hirame) guide
• Best lures for Japanese flounder
• Enshu-nada report, late October 2026
• Aori-ika (bigfin reef squid) guide
• Berkley PowerBait CullShrimp: the New Pre-Rigged Shrimp

MINAGIMAN

JAPAN ANGLER

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Born in 1994. Originally from Hyogo Prefecture, I moved to Iwata City in Shizuoka Prefecture in search of the sea. I am an Enshunada surf angler who enjoys surf fishing. I am also active on YouTube, and my fishing grounds range from Irago to Iwata.